Pressure resistance of cold-shocked Escherichia coli O157:H7 in ground beef, beef gravy and peptone water.

AIMS: (i) To study the effects of cold shock on Escherichia coli O157:H7 cells. (ii) To determine if cold-shocked E. coli O157:H7 cells at stationary and exponential phases are more pressure-resistant than their non-cold-shocked counterparts. (iii) To investigate the baro-protective role of growth media (0·1% peptone water, beef gravy and ground beef). METHODS AND RESULTS: Quantitative estimates of lethality and sublethal injury were made using the differential plating method. There were no significant differences (P > 0·05) in the number of cells killed; cold-shocked or non-cold-shocked. Cells grown in ground beef (stationary and exponential phases) experienced lowest death compared with peptone water and beef gravy. Cold-shock treatment increased the sublethal injury to cells cultured in peptone water (stationary and exponential phases) and ground beef (exponential phase), but decreased the sublethal injury to cells in beef gravy (stationary phase). CONCLUSIONS: Cold shock did not confer greater resistance to stationary or exponential phase cells pressurized in peptone water, beef gravy or ground beef. Ground beef had the greatest baro-protective effect. SIGNIFICANCE AND IMPACT OF THE STUDY: Real food systems should be used in establishing food safety parameters for high-pressure treatments; micro-organisms are less resistant in model food systems, the use of which may underestimate the organisms' resistance.

Manufacture of spent hen ayami and its utilisation in meatloaf and fresh sausage.

1. Spent hens were slaughtered, hand deboned and then further processed into a surimi-like material, ayami, which was used to manufacture meatloaf and fresh sausage as value-added products. 2. Yields of deboned muscle and of ayami (% of deboned muscle) were 34.4 to 43.7% and 63.6%, respectively. 3. The ayami composition was: moisture 78.3%, ash 0.28%, fat 3.7%, protein 15.3% and carbohydrate 2.4%. Its pH value ranged from 5.65 to 6.10, and the water-holding capacity from 35.6 to 37.8. 4. Three formulations of meatloaf were prepared with 0, 7.5 and 15% chicken fat and with a blend of herbs and spices. The most acceptable of the three was used for the manufacture of meatloaf and fresh sausage. 5. Microbial testing was conducted on freshly prepared formulation of the meatloaf (15% fat) and sausage, and on frozen stored samples (-18 degrees C, 10 d). All had acceptable microbial quality. 6. Sensory analysis showed that the 15% fat formulation of the meatloaf was the most liked and the fresh sausage was consumer acceptable.

Food saftey: an examination of the potential impact on the economies of countries of the Caribbean Community [abstract]

Food safety pertains to the prevention, reduction or elimination of the risk of ill-health as a result of the consumption of foods whether fresh or processed, obtained through the domestic market or by international trade. Food saftey issues therefore impact on agricultural production and trade, as well as on the manufacture of processed foods and on the preparation and service of meals, whether these be in a hotel/restaurant environment or by itinerant street vendors. Agricultural production, trade and tourism are together significant contributors to the output of the open economies of the countries of the Caribbean Community. The discussion examines the findings of a recent assessment of the food safety status of Caribbean Community (CARICOM) Member States, which focussed on food safety in respect of plant, animal and human health systems in the various countries. The economic structure of selected countries is highlighted together with an indication of the trends in trade. The findings of the food safety assessment are then reviewed in the context of their possible impact on the economic output of the countries. The analysis showed that agricultural production and trade play a critical role in the economic output of many CARICOM States, Through their contribution to export earnings as well as employment. Tourism is also important in this regard. Inadequate attention to food safety issues can result in loss of market share either through a shift in purchasing patterns as experienced by other countries, or through detention by the regulatory agency of the importing country. Weak food safety policies could also jeopardize the tourism sector. Improvements in the food safety system and its infrastructure would serve to enhance the earning potential of the agricultural and tourism sectors and this should lead to greater economic output from those sectors. (AU)

Emergence of salmonella enteritidis in the Caribbean: case control study in Trinidad and Tobago

OBJECTIVE: To determine the aetiology, sources and risk factors of Salmonella enteritidis (SE) infections in Trinidad and Tobago. METHODS: A prospective case control study of 46 cases and 92 age-and neighbourhood-matched controls was conducted between March 1998 and May 1999 to explore hypothesized risk factors for SE infections. A written questionnaire was administered through face-to-face interviews. Standard culture and serological laboratory methods were used to confirm SE isolates from food and clinical samples. Data were analyzed using Epi Info version 6.04 software. RESULTS: SE infection was associated with the consumption of shell eggs, particularly raw or undercooked eggs. There was a positive association between SE infection and the number of eggs consumed (p<0.001). Persons with SE infection were less likely than well controls to purchase refrigerated eggs and to refrigerate their eggs at home (p<0.001). SE isolates from 30/34 (88 percent) patients and from 9 implicated egg or egg-containing food samples were phage type (PT) 4. Thirty (65 percent) of 46 patients were hospitalised and 2 died. CONCLUSION: SE infection are sporadic and seasonal and are associated with eating raw-egg foods such as homemade eggnog and ice cream, cake batter and egg-containing beverages. PT 4 is the dominant phage type. Public health education programmes on the risks of eating raw or undercooked eggs, egg-traceback studies and on-farm testing of flocks for SE are needed to reduce the incidence of this infection.(AU)

Salmonellosis in Trinidad: evidence of transovarian transmission of salmonella in farm eggs

The aim of this study was to determine whether the contents of farm eggs in Trinidad are contaminated with Salmonella and if transovarian transmission occurs. 750 fresh eggs from 10 farms supplying 75 percent of the country's eggs were cultured for Salmonella. Salmonella was found on the egg shells' surface from all farms, and in the egg contents from three farms. Isolates were obtained from the cultures of the contents and shells of nine (1.2 percent) and 35 (4.66 percent) eggs, respectively (p<0.005). Serotypes found in the contents were S. enteritidis (0.8 percent; deduced to be contaminated by transovarian transmission) were S. typhimurium (0.4 percent); those isolated from the shells (contaminated by faecal transmission) were S. typhimurium (3.06 percent), S. enteritidis (0.67 percent), S. ohio (0.27 percent), S. cerro (0.27 percent) S. infantis (0.27 percent) and S. heidelberg (0.13 percent). This study provides the first evidence for Salmonella and more, importantly, S. enteritidis, in eggs in Trinidad. This is of major public health significance because S. enteritidis infected eggs appear normal and the organism is difficult to detect and control. The consumption of these eggs may increase the risk of Salmonella infection. Food safety practices, particularly the thorough cooking (>70 degree census) of all egg dishes and the refrigeration (<10 degree census) of shell eggs and egg dishes, are recommended.(AU)